Methods for performing operations in a well bore



Fzpmii B. P. NUTTER June 27, 1967 METHODS FOR PERFORMING OPERATIONS IN A WELL BORE 6 Sheets-Sheet 1 Original Filed Nov. 6, 1964 I NVENTOR.

B. PJNUTTER- 3,327,781 METHODS FOR PERFORMiNG OPERATIONS IN A WELL BORE 6 Sheets-Sheet 2 June 27, 1967 Original Filed Nov. 6, 1964 INVENTOR.

B. P. NUTTER 3,327,781

METHODS FOR PERFORMING OPERATIONS IN A WELL BORE June 27, 1967 6 Sheets-Sheet 5 Original Filed Nov. 6, 1964 Be/ybm/n R N0 2 2 er INVENTOR.

June 27, 1967 Original Filed Nov. 6, 1964 B. P. NUTTER METHODS FOR PERFORMING OPERATIONS IN A WELL BORE 6 Sheets-Sheet 4 INVENTOR.

June 1967 B. P. NUTTER 3,327,781

METHODS FOR PERFORMING OPERATIONS 1N A WELL BORE Original Filed Nov. 6, 1964 6 Sheets-Sheet 5 f I --r1 mum ,l -isa June 27, 1967 B. P. NUTTER METHODS FOR PERFORMING OPERATIONS IN A WELL BORE 6 Sheets-Sheet 6 Original Filed Nov. 6, 1964 INVENTOR.

United States Patent 3,327,78 METHODS FOR PERFORMING OPERATIONS IN A WELL BORE Benjamin P. Nutter, Houston, Tex., assignor to Schlumberger Technology Corporation, Houston, Tex., a corporation of Texas Original application Nov. 6, 1964, Ser. No. 410,828, now Patent No. 3,291,219, dated Dec. 13, 1966. Divided and this application Apr. 21, 1966, Ser. No. 544,162

7 Claims. (Cl. 166-3) This application is a division of application Ser. No. 410,828, filed Nov. 6, 1964, now Patent No. 3,291,219 which was a continuation-in-part of application Ser. No. 143,731, filed Oct. 9, 1961, now abandoned.

This invention relates to well tools and, more particularly, to well testing tools of the type having a packer assembly which is positioned within the well bore by means of a string of drill or other well pipe and having a retrievable sampler assembly which is lowered and raised through the bore of the pipe string to perform multiple testing and treating operations successively without removing the pipe string from the well.

In well-testing operations it is desirable to recover an uncontaminatedsample of the formation fluids. However, most potentially productive formations are invaded by a fluid filtrate derived from the drilling fluid which fills the Well bore during the drilling and testing operations. This filtrate may be produced in substantial quantities along with the formation fluids, particularly during the early periods of a flow test. It therefore would be of value to conduct a flow test so that the produced fluids are recovered in discrete quantities segregated according to their order of production or to recover successive flow samples without re-exposing the formation to drilling fluid pressure and contamination between tests.

Moreover, it is further desirable in well-testing operations to obtain accurate measurements of various formation pressures. Of particular interest to Well operators is the formation shut-in pressure, i.e., the actual hydraulic pressure within the virgin formation, Before a shut-in pressure measurement can be obtained, fluid from the isolated section of the borehole must be allowed to flow into the testing tool for a short period of time in order to relieve trapped hydrostatic drilling fluid pressure and the squeeze pressure imposed by setting the packing means. However, if the formation is allowed to flow for too long a period before taking the shut-in measurement, the pressure near the well bore will have decreased and considerable time may be required for the true formation pressure to be re-established adjacent the borehole. This is particularly true for formations of low permeability. With present well-testing tools, it is often difficult to control'the length of this initial flow period with sufficient accuracy to insure a good shut-in pressure measurement. Thus, it would be desirable to provide a well testing tool having valve means which may be operated simply and positively from the surface.

It is further desirable during a well-testing operation that drilling fluid circulation may be maintained as continuously as possible and that the testing be conducted with a minimum of delay to drilling operations. With conventional Well-testing equipment, fluid circulation must often be interrupted for excessively long periods of time. Thus in particular areas where, for example, excessive caving of the well wall may occur unless fluid circulation is maintained, the time available for Well-testing operations may be severely limited and testing is often completely prohibited by the necessity of maintaining fluid circulation. Thus, it would be advantageous to provide a well-testing tool which may be operated with minimum interruption of drilling fluid circulation.

3,327,781 Patented June 27, 1967 Accordingly, it is an object of the invention to provide means with w b i c,h t r eating ,opgra,tions may he erformed, formation pressure measurements taken and samples of formation fluids recovered successively from a plurality of zones within a borehole without removing the pipe string from the well between successive tests.

A further object of the invention is to provide a testing tool with which formation pressure measurements and samples o f fo r natiorif fluids mafia ie covered successively from the same" zone without re-exposing the formation to well-fluid pressure and contamination by borehole fluids between successive tests.

A further object of the invention is to provide a testing tool which may be utilized on a drill string to meas ure formation pressure and successive samples of formation fluids which may be obtained during drilling operations.

Still a further object of the invention is to provide a testing tool with which formation shut-in pressure measurements may be obtained before or after fluids have been allowed to flow from the test zone or at any time during the testing operation.

Yet another object of the invention is to provide a testing tool of the above-described type with which circulation of drilling fluid may be maintained in the tool and within the well bore before and after successive sampletaking operations, even with packers set.

These and other objects are attained, in accordance with the invention, by providing a well tool with a tubular body member having a bore which continues the bore of the pipe string in which it is connected. At least one packer is carried by the body member for packing off a zone of the well bore opposite a lateral test passage through the body member. In some embodiments of the invention, the well tool is particularly adapted for conducting tests and treating operations with a drill bit attached below the tool so that the tool may be used without removing the pipe string during drilling operations.

A retrievable valve assembly, when seated in the bore of the body member, has cooperatively arranged valve means for controlling fluid communication via the test passage to chambers in the assembly.

For convenient remote operation of the tool, the chamber valve means opens in response to fluid pressure applied from the surface. Such fluid pressure may also be used to expand the packer or packers carried by the body member and they may remain expanded, if desired, after the valve assembly is retrieved. Selectively, the test passage may be left in a closed position when the assembly is retrieved to isolate the packed-off Zone from well bore fluids. Provision is also made for circulation of fluid through the pipe string even when the packer or packers remain set. By appropriate arrangement of pressure-measuring means within the assembly, shut-in pressure measurements may be secured when desired.

The invention and others of its objects and advantages will become apparent from the following description, taken in conjunction with the accompanying drawin gs, in which:

FIG. 1 is a schematic diagram showing the packer assembly portion of a well tool disposed within a borehole at the end of a pipe string and showing the retrievable portion of the tool being lowered through the bore of the string;

FIG. 2 is a simplified view, in longitudinal section, of one embodiment of the packer assembly portion of a Well tool showing the parts of the apparatus in the positions normally occupied when the pipe string is being raised or lowered within the Well bore;

FIG. 3 is a further view of the apparatus of FIG. 2, showing a retrievable portion of the tool, partly in longitudinal section, seated within the packer assembly;

FIG. 4 is a further view, in longitudinal section, of the apparatus illustrated in FIG. 3, showing the parts of the tool in the positions normally occupied when a fluid sample is being taken;

FIG. 5 is a fragmentary view of the upper portion of the packer assembly shown in FIGS. 2 through 4, and a portion of a modified retrievable assembly for use when taking the final fluid sample from a specific test zone.

FIG. 6 is a schematic diagram of another embodiment of the invention showing the packer assemly portion of a well tool attached to a string of drill pipe within a bore hole and showing the retrievable portion of the tool being lowered through the bore of the pipe string;

FIG. 7 is a simplified view, in longitudinal section, of an embodiment of the packer assembly portion of a well tool for use in testing and treating operations during drilling;

FIG. 8 is a transverse sectional view taken along the line 88 of FIG. 7;

FIG. 9 is a transverse sectional view taken along the line 99 of FIG. 7;

FIG. 10 is a further longitudinal view, partially in section, of the retrievable portion of the apparatus of FIG. 6 and a detachable barrier valve member;

FIG. 11 is a further view, partly in longitudinal section, of the apparatus illustrated in FIGS. 7 and 10 showing parts of the tool in the positions normally occupied when successive fluid samples are being taken from a test zone;

FIG. 12 is a view, partly in longitudinal section, showing the apparatus of FIG. 11 with the parts in the positions normally occupied when the shut-in pressure is being recorded;

FIG. 13 is a view, in longitudinal section, showing the apparatus of FIG. 11 after a sample has been retrieved and the barrier valve member is seated in the body of the tool;

FIG. 14 is a view, in longitudinal section, showing a retrievable assembly for use in releasing the packer and retrieving the barrier valve member after the final operation at a specific zone, and

FIG. 15 is a fragmentary sectional view of the upper portion of a modified form of retrievable valveassembly adapted for introducing fluids into a zone in a well bore.

Referring now to the drawings, in FIG. 1 there is illustrated a borehole 10 drilled through earth formations and filled with a drilling fluid 11. A pipe string 12 is suspended from the floor of a drilling platform 13 by means of tapered slips 14 and may be raised or lowered in the well bore by means of conventional apparatus (not shown). A fluid pump 15 has an intake conduit 16 submerged within a drilling fluid reservoir 17 and an outlet conduit 18 connected to the bore of the pipe string 12. Thus, fluid pressure may be applied within the pipe string 12 to circulate the drilling fluid in a conventional manner or to operate the well tool, as will be described hereinafter.

In one embodiment of an apparatus for practicing the present invention, the well tool comprises a packer assembly 19, which is adapted to be connected to the pipe string 12 for positioning at any desired level within the well bore, and a retrievable assembly 20, which is adapted to be raised or lowered within the pipe string 12 by means of a wire line 21 spooled upon, and driven by, a power winch 22. At the lower end of the packer assembly 19, there may be attached a perforated plug 23 which facilitates entry of the packer assembly into the well bore 10 and allows circulation of drilling fluid through the pipe string. A pressure lubricator device 24 permits entry of wire line 21 into the bore of the pipe string without loss of fluid pressure which may be applied therein.

To assist in understanding the invention, a simplified description of the structure and operation of one embodiment will first be given with reference to FIGS. 2-5.

With reference to FIG. 2, the packer assembly 19 includes a tubular body member 30 which may have its upper end adapted for threaded, fluid-tight connection i to a pipe string that shown) and its lower end adapted for threaded connection to a perforated plug (not shown). A pair of annular, pliable, expansible packers 31 and 32 are supported about the exterior of the body member 30 and separated 'by a spacer sleeve 33 which is slidably fitted about the body member to accommodate changes in packer length. The upper end of upper packer 31 is connected to body member 30 and the lower end of lower packer 32 is connected to a hydraulic return sleeve 34 which is slidably received about the body member. Return sleeve 34 and body member 30 have interengaging stepped surfaces which define a sealed hydraulic packer return chamber 35, as best seen in FIG. 4.

Annular spaces 36 and 37 between each of the packers 31 and 32 and the body member 30 are connected via a passage 38 through the spacer sleeve 33 and together form a sealed packer inflating chamber. The upper end of the inflating chamber 36438 is connected to the bore of body member 30 by means of an inflating passage 39, and a check valve 40 permits entry of fluids from the bore of the body member into the inflating chamber but prevents fluid flow in the opposite direction. A deflating passage 41 through the body -member.'30 allows fluids trapped within the inflating chamber 36-38 to be exhausted into the bore of the body member.

An equalizing passage 42 and a test passage 43 extend through body member 30 and spacer sleeve 33 and are each appropriately sealed to provide separate fluid channels between the 'bore of the body member and the portion of the well bore adjacent the spacer sleeve. A check valve 44 may be located in test passage 43 to permit entry of fluids from the well bore but prevent fluid flow in the opposite direction.

A tubular sleeve member 50 slidably mounted for limited longitudinal movement within the bore of body member 30 functions as a valve means for various passages in the body member by the location of various passages through the sleeve member. Body member 30 has a bore of generally uniform diameter to receive and seal with the retrievable assembly 20. The sleeve 50 is provided with a test and equalizing passage 51, a deflating passage 52, and a series of O-rings which cooperate to valve selectively the deflating, equalizing and test passages 41, 42 and 43. Downward and upward movement of sleeve member 50 is limited by interengagement of shoulders 53, 54 and 55, 56 located at the upper and lower portions, respectively, of the sleeve member 50 and body member 30. A spring 57 acts in compression between shoulders 58 and 59, located on body member 30 and sleeve member 50, respectively, to urge the sleeve toward its uppermost position; and a resiliently expansible snap ring 60 is mounted in the bore of the body member to releasably lock the sleeve member in its lowermost position and to releasably retain the sleeve in its uppermost position.

When the sleeve member 50 is in its uppermost position, its test and equalizing passage 51 registers in sealed communication with the body member equalizing passage 42, and its deflating passage 52 registers with the body member deflating passage 41. In the lowermost position of the sleeve member 50, the body member equalizing passage 42 and deflating passage 41 are closed by O-rings, and the sleeve member test and equalizing passage 51 registers in sealed communication with the body member test passage 43.

Continuous pressure equalization between the portions of the well bore above and below the packer devices 31 and 32 is provided by a pressure by-pass passage 64, which comprises a lateral passage 65 through the upper end of body member 30, a sealed annular space 66 is defined by the upper portions of the body member bore and periphery of sleeve member 50 and extending past shoulder 53, a longitudinal passage 67 through the central perforated plug 23. By-pass passage 64 also permits circu lation of drilling fluid when the packers devices are expanded except when the retrievable assembly 20 is seated in the sleeve member 30.

The retrievable assembly 20, shown in seated position within the packer assembly 19 in FIGS. 3 and 4, comprises a sampler valve section 70 which may be slidably received within the bore of sleeve member 50 and a sample chamber section 71 which is connected to the upper end of valve section 70. A wire line 21 may be attached in a conventional manner to the upper end of the sample chamber section 71 to raise or lower the retrievable assembly 20 within the bore of the pipe string 12.

The sampler valve section 70 comprises two telescopically arranged members, an outer valve sleeve 72 and an inner valve mandrel 73, which have interengaging surfaces at their lower end to limit relative movement between an extended position (FIG. 3) and a retracted position (FIG. 4). A tapered shoulder 74 at the upper end of the valve sleeve 72 interengages with a tapered shoulder 75 at the upper end of the sleeve member 50 to support the retrievable assembly 20 in a seated position within the bore of the sleeve. A spring 76 acts in compression between valve sleeve 72 and mandrel 72 to urge them toward their extended position.

When the retrievable assembly 2t) is in its seated position within the bore of the sleeve member 50 (FIGS. 3 and 4), the bore of the packer assembly 19 is closed to downward fluid flow by O-rings 80, 81 and 82, which seal between the body member 30, sleeve 50, sampler valve sleeve 72, and sampler valve mandrel 73, respectively; and fluid pressure applied by means of pump to the bore of pipe string 12 will act upon valve mandrel 73 to urge it downwardly against the force of spring 76. The weight of the sampler valve mandrel 73 and the sample chamber section 71, the diameter of the valve mandrel, and the spring rate of the sampler valve spring 76 are so chosen that the valve mandrel will be moved to its retracted position whenever a predetermined pump pressure is applied. The upper side of the upper O-ring 82 around the sampler valve mandrel 73 is exposed to the hydrostatic pressure within the bore of the pipe string 12 and the lower face of the lower O-ring 83 around the valve mandrel is exposed to the hydrostatic pressure in the annulus between the well walls and the pipe string via the pressure by-pass passage 64 (even when the packers 31 and 32 are set) and the ports 84 located in the lower end of the 73 valve sleeve 72. Therefore, the valve mandrel 73 is pressure-balanced within the valve sleeve 72 insofar as the hydrostatic head of the drilling fluid is concerned when the same hydrostatic head exists within and outside the pipe string.

The interior of the valve mandrel 73 is divided into two separate compartments 90 and 91 by a bore-closing portion 92 near the lower end of the mandrel. The upper compartment 90 forms a sample-receiving conduit which opens into the sample chamber section 71 and the lower compartment 91 forms a closed shut-in pressure chamber. Conventional time-pressure recorders 93 and 94 are mounted in each of shut-in pressure chamber 91 and sample chamber section 71, respectively.

Valve means are provided for placing selectively either the shut-in pressure chamber 91 or both the shut-in pressure chamber and the sample-receiving conduit 90 in fluid communication with the sleeve member test and equalizing passage 51. The valve means comprises a pair of longitudinally spaced passages 95 and 96 through the sampler valve sleeve 72 and a pair of longitudinally spaced passages 97 and 98 through the valve mandrel 73. The passages 95, 9'6 and 97, 98 are so positioned and spaced that, in the extended position of mandrel 73 relative to sleeve 72 (FIG. 3), the lower passage 98 through the mandrel registers with the upper passage 95 through the sleeve 72 and only the shut-in pressure chamber 91 is in fluid communication with the sleeve member test and equalizing passage 51; whereas, in the retracted position of the mandrel relative to the sleeve 72 (FIG. 4), both the upper and lower passages 97 and 98 through the mandrel register with the upper and lower passages and 96, respectively, through the sleeve 72. Fluid communication is thereby provided from the sleeve member test and equalizing passage 51 to both the sample-receiving conduit 90 and the shut-in pressure chamber 91.

The sample chamber section 71 of the retrievable assembly 20 may comprise a plurality of series-connected sample-receiving chambers, through only two such chambers 100 and 101 are shown in FIG. 4. A back pressure or check valve 102 is placed in the passage 103 between the adjacent chambers 100, 101 and is arranged to permit entry of fluids from the sample-receiving conduit 90 but to prevent fluid flow in the opposite direction. Y

In FIG. 5 there is shown a portion of a modified retrievable assembly 20' for use when taking the final fluid sample from a specific test zone. Modified assembly 20" is identical in all respects with retrievable assembly 20 (FIGS. 3 and 4) except that the modified version, the upper portion of sampler valve sleeve 72' is enlarged in diameter and a snap ring is disposed in a peripheral groove formed in the outer surface of the sampler valve sleeve 72'. The enlarged-diameter portion of the sleeve 72 and the snap ring 110 function to release the sleeve member 50 from its locked lowermost position in a manner to be described hereinafter. v.

To perform testing operations within a well bore, the packer assembly 19 is connected at the end of a :pipe string 12 with the assembly being in the position shown in FIG. 2. The pipe string 12 is then lowered into the well bore 10 until the packer assembly 19 is positioned opposite the zone to be tested, as for example, zone 26 shown in FIG. 1. During the lowering operation the bore of the pipe string 12 fills with drilling fluid 11 which enters through the perforated plug 23. Thus, at any time during the lowering operation, drilling fluid 11 may be pumped downwardly through the bores of the pipe string 12 and packer assembly 19 and out of the perforated plug 23 to return to the surface via the annulus between the pipe string and the well wall. The sleeve member spring 57 and the snap ring 60 hold the sleeve member 50 in its uppermost position so that the equalizing passages 42, 51 and the deflating passages 41, 52 are open.

When the packer assembly 19 is positioned opposite the test zone 26, the retrievable assembly 20 shown in FIGS. 3 and 4 may be lowered through the bore of the pipe string 12 to its seated position within the packer assembly. After the sampler valve sleeve shoulder 74 lands on the sleeve member shoulder 75, the weight of the retrievable assembly 20 compresses the sleeve member spring 57 and moves the sleeve member 50- downwardlv to its lowermost position. The parts of the well tool w'll then be in the positions shown in FIG. 3, with the equalizing passage 42 and the body deflating passage 41 being closed and the test passage 43 in fluid communication with the shut-in pressure chamber 91 via sleeve member passage 51 and sampler valve assembly passages 95 and 98.

The pressure lubricator device 24 (shown in FIG. 1) may then be closed and fluid pressure applied to the pipe string 12 by means of pump 15. Since the bore of the packer assembly 19 is now closed, the fluid pressure within the pipe string 12 forces fluid through the inflating check valve 40 and into the inflating chamber 36-38 to expand packers 31, 32 into sealed engagement with the well wall, as shown in FIG. 4. As previously mentioned, the sampler valve mandrel 73 remains in its extended position relative to sampler valve sleeve 72 until the pump pressure within the pipe string 12 is further increased to a predetermined value which may, for example, be 750 p.s.i.g. The predetermined value chosen should be sufficiently high that the pressure within the packers 31 and 7 32 will support the pressure-differential across their ends when the test zone 26 is opened to the atmospheric pressure within chambers 100, 101 of retrievable assembly 20.

As the pump pressure is increased above the predetermined value, the sampler valve mandrel 73 is moved downwardly to its retracted position relative to the sampler valve sleeve 72, thereby moving mandrel passage 97 into registry with sleeve passage 95 and placing the sample-receiving conduit 90 in fluid communication with the surrounding formation test zone 26 via passages 97, 95, 51 and 43, as shown in FIG. 4. The shut-in pressure chamber 91 remains in fluid communication with the test zone 26 via passages 98, 96, 51 and 43.

As the sample-receiving chambers 100, 101 are filled with test fluids, check valve 102 functions to substantially segregate the produced fluids according to their order of production. If desired, however, check valve 102 may be replaced by a choke orifice.

After suflicient time has elapsed for reception of the fluid sample into the sample-receiving chambers 100, 101, the pump pressure is released from the bore of the pipe string 12 leaving onlyhydrostatic pressure which allows the sampler valve spring 76 to return the sampler valve mandrel 73 to its extended position. Thus, passage 97 is closed to entrap the received fluid sample within the sample-receiving chambers 100, 101. The retrievable assembly 20 then may be lifted to the surface by means of wire line 21 and the entrapped fluid sample examined and analyzed.

When the retrievable assembly 20 is removed from packer assembly 19, snap ring 60 holds the sleeve member 50 in its lowermost position. Drilling fluid may be circulated through the base of pipe string 12, by-pass 66, and the annulus around :pipe string 12. The equalizing passage 42 and the deflating passage 41 therefore remained closed. The expanding check valve 411 prevents escape of the fluid trapped in the expanding chamber 36- 38 to maintain the packers 31 and 32 in sealed engagement with the well wall. The check valve 44 located in the packer assembly test passage 43 prevents entry of drilling fluid 1-1 from the bore of the pipe string 12 into the portion of the well bore located between the expanded packers 31 and 32 so that the test zone 26 remains isolated from drilling fluid pressure and contamination while the retrievable assembly 20 is being withdrawn to the surface.

The same or another retrievable assembly 20 may then be lowered through the pipe string 12 and a second fluid sample may be taken. This procedure may be repeated as many times as desired until a satisfactory fluid or pressure analysis of the test zone has been made.

For the final sample-taking operation from sealed-off test zone 26, the retrievable assembly 20 having a modified sampler valve sleeve 72, as shown in FIG. 5, is lowered into seated position within packer assembly 19. Pump pressure is again applied and a fluid sample taken in the manner previously described. When modified retrievable assembly 20' is lifted from its seated position within packer assembly 19, the enlarged-diameter portion of the sampler valve sleeve 72' holds snap ring 60 in its expanded condition until the upper end of the sleeve member 50 has moved into a position opposite the snap ring. The snap ring 110 carried by the modified sampler valve sleeve 72' transmits the force of the upward movement of the sampler valve sleeve 72 to the sleeve member 50 and assists spring 57 in moving the sleeve member 50 upwardly. Thus, when the modified retrievable assembly 20' is removed from the packer assembly 19, the sleeve member 50 is returned to its uppermost position as shown in FIG. 2. This upward movement of the sleeve member 50 opens the deflating passage 41 and relieves the fluid pressure from the packer inflating chamber 36-38. At the same time, the equalizing passage 42 is opened to allow hydrostatic pressure to return to the portion of the well bore between packers 31 and 32, thereby facilitating deflation of the packers. The packer return chamber 35 aids in returning packers 31 and 32 to their deflated condition. When the packers 31 and 32 are deflated, return sleeve 34 is pulled upwardly, thus increasing the volume of vacuum chamber 35. Since the chamber 35 is sealed, the pressure within it is extremely low and the high hydrostatic fluid pressure outside the chamber tends to urge the return sleeve 34 back toward its lower position, as shown in FIG. 3. In this manner, full collapse of the deflated packers 31 and 32 is ensured.

The packer assembly 19 may then be moved upwardly or downwardly in the borehole 10 to be positioned opposite another test zone, whereupon further sample-taking operations may be repeated in the manner previously described.

During a sample-taking operation, the formation shutin pressure may be measured by one of two methods, the first method utilizing the upper and lower pressure recorders 93, 94 and the second method utilizing the lower pressure recorder 93 alone. By the first method, the sampler valve assembly 70 is maintained in its retracted condition (FIG. 4) until the sample-receiving chambers are filled whereupon the pressure recorders 93, 94 measure the formation shut-in pressure. However, it may not be possible to use this method in all cases. For example, if the test zone is relatively impermeable, an excessive amount of time may be required to fill the sample-receiving chambers or, as previously mentioned, the pressure in the formation immediate to the Well bore may decrease during the flow period and may not be restored to the true formation pressure within a reasonable period of time. Under such conditions, the second method of measuring pressure utilizing only pressure recorder 93 may be employed.

In accordance with this second method of measuring pressure, the pump pressure in the bore of the pipe string is raised momentarily above the predetermined value to allow the test zone to flow for a short period of time into the sample-receiving chambers 100, 101 in order to relieve the hydrostatic drilling fluid pressure and the packer squeeze pressure trapped between packers 31 and 32. Due to the relatively small volume of the annulus that is isolated by the packers 31 and 32, only a few seconds of flow should be required to relieve these pressures. The pump pressure is then reduced so that the sampler valve assembly 70 may return to its extended condition (FIG. 3) and terminate the flow period. If the formation fluids are allowed to flow into the smear/- ing chambers 100, 101 fo; o nly a shopt period of time, then the formation pressure near th well bore will not have decreased materially and the lower pressure recorder Q 3 will record the true or initial"shut-inpressure. The pump pressure may then be raised above the predetermined value to move the sampler valve assembly 70 to its retracted condition (FIG. 4) so as to complete the flow test and, in many instances, to obtain a record of final shut-in pressure, as well. Since only a simple change in pump pressure is required to operate the sampler valve assembly 70, the flow test may be interrupted at any time and a remeasurement of the shut-in pressure made The pressure recorder 94 located in the sample receiving chamber will record all pressures in the chamber during the sample-taking operation and will therefore provide a measure of the formation flow pressure.

Another embodiment of an apparatus for practicing the present invention is illustrated in FIGS. 6-15, this embodiment being particularly adapted for testing and treating operations conducted during drilling of a well. In FIG. 6, a packer assembly 19h is shown installed as an integral part of a pipe string 12 within a borehole 10. Attached to the packer assembly 19h is drill bit 300. A retrieva'ble assembly 20h is adapted to be raised or lowered within the pipe string 12 by means of a wire line 21 spooled upon, and driven by, a power winch 22 and is shown as it is being lowered into the pipe string 12.

The packer assembly 19h of FIG. 7 includes a tubulat body member 301 connected at its upper end to the pipe string 12 and to the drill bit 300 at its lower end. A single, pliable, expansible packer element 302 is supported about the exterior of the 'body member 301 with its ends connected to the body member 301. The annular space 303 between the packer element 302 and body 301 is connected to spaced-apart positions of the central bore of the body by longitudinal passages 304, 305 extending through the body. In one of these passages, inflating passage 304, a check valve 306 is provided to permit the flow of fluids into passage 304 from the central bore of the body member 301 to the annular space 303, but prevent fluid flow in the opposite direction. In the other of these passages, deflating passage 305, a check valve 307 is provided to permit flow of fluids from the annular space 303 into the central bore of the body 301 and to prevent flow in the opposite direction.

A tubular sleeve member 50h is slidably mounted for limited longitudinal movement within the bore of the body member 301. Spaced-apart lateral passages through the sleeve member 50h provide a sleeve fluid passage 308 and a sleeve by-pass passage 309. A sleeve spring 313 acts in compression between shoulders 314 and 315 located on the body member 301 and the sleeve member 5011, respectively, to urge the sleeve member towards its uppermost position. A resiliently contractible snap ring 316 is mounted in the bore of the body member 301 to releasably lock the sleeve member 50h in its lowermost position and to releasably retain the sleeve member in its uppermost position. Downward movement of the sleeve member 50h is limited by interengagement of shoulders 315 and 310 on the sleeve member 50h and the body members 301, respectively.

A by-pass passage 317 through the body member 301 provides communication from the annulus of the well bore above the packer element 302 to the central bore of the body member at a position adjacent the lower end of the sleeve member 50h and below the sleeve fluid passage 308. The by-pass passage 317 registers with the sleeve by-pass passage 309 when the sleeve member 50h is in the lower position and it is closed by O-rings 318 and 319 when the sleeve member 50h is in the upper position.

A body fluid passage 320 through the body member 301 provides communication from the annulus of the well bore 10 below the packer element 302 to the central bore of the body member at a point substantially above the lower portion of the sleeve member 50h. A check valve 326 is provided in passage 320 to permit flow of fluid from the annulus through the body member 301, but to prevent flow in the reverse direction the upper end of fluid passage 320 registers with sleeve fluid passage 308 when the sleeve member 50h is in the lower position and these fluid passages are sealed against contamination by drilling fluid or other fluids by means of O-rings 323 and 324.

The retrievable assembly 20h illustrated in FIG. 10 is shown seated within the packer assembly 19h in FIGS. 11 and 12. The Valve section 70h or assembly 20h is adapted to be slidably received within the bore of the sleeve member 50h. The valve section 70h comprises two telescopically arranged members, an outer valve sleeve 72h and inner valve mandrel 73h, which respectively have interengaging surfaces to limit their relative movement between an extended position and a retracted position. In the extended position (FIGS. 10 and 12), shoulder 330 on the valve mandrel 73h engages shoulder 331 at the bottom of the valve sleeve 72h to limit the extent of movement; and, in the retracted position (FIG. 11), shoulder 332 on the mandrel engages shoulder 333 at the upper end of the valve sleeve. A valve assembly spring 334 is positioned to act in compression between the shoulder 333 at the upper end of the valve sleeve 72h and a shoulder 335 at the base of the valve assembly chamber 71h.

As seen in FIGS. 10 through 14, a barrier valve member 336 comprising a barrier mandrel 339 and a barrier sleeve 341 is dependently mounted from the inner valve mandrel 73h. This barrier valve 336 is adapted to be received within a reduced portion 321 of the central bore of the body member 301 and fluidly sealed therein by an O-ring 337 around the barrier sleeve 341. The barrier valve 336 together with check valve 326 have a primary function of preventing drilling fluid from passing downwardly through the body of the tool into the packed-off zone of the well bore 10 between sampling operations and a further function, in cooperation with by-pass pas sage 317, of permitting equalization of the hydrostatic pressure in the annulus of the well bore 10 above the packer elements 302 and within the central bore of the sleeve member 50h without introducing drilling fluid into the packed-off zone below the packer element 302 when the sleeve member 50h is in its lower position.

The barrier valve 336 may be positioned in the lower portion of the body member 301 by any suitable means, such as the detachable connection by means of shear pin 338 passing through barrier mandrel 339 and a lower extension of valve mandrel 73h as shown in FIG. 10. The barrier sleeve 341 is provided with lateral ports 340; and a passageway 342 in the barrier mandrel 339 communicates with ports 343 therein. Movement of barrier valve mandrel 339 relative to barrier valve sleeve 341 is limited in the upward direction by interengagement of shoulders 344a and 344b on the barrier mandrel 339 and barrier sleeve 341, respectively. Movement of barrier valve mandrel 339 in the downward direction is limited by interengagement of shoulders 3440 and 344d on the barrier mandrel and barrier sleeve 341, respectively.

In the extended position of the barrier mandrel 339 relative to the barrier sleeve 341, the ports 340, passageway 342 and ports 343 provide fluid communication through the barrier valve 336 permitting equalization of pressure above and below the O-ring 337 when the barrier valve is seated within the reduced bore portion 321 of the body 301 of the packer assembly 1911. The barrier valve member 336 is further provided with a check valve 346 to release whatever pressure that may build-up below the barrier valve during the expansion of the packer element 302 but to prevent the passage of drilling fluid downwardly through the barrier valve member. When the barrier mandrel 339 is in the retracted position, the ports 340 in the barrier sleeve 341 are closed by O-rings 347 and 348.

When the retrievable assembly 20h is in its seated position with the bore of sleeve member 50h (FIGS. 11 and 12), the bore of the packer assembly 19h is closed to downward fluid flow by O-rings 350, 351 and 352, which seal between the body member 301, sleeve member 5011, valve sleeve 72h and valve mandrel 73h, respectively. Fluid pressure applied by means of pump 15 to the bore of the pipe string 12 will act upon the valve mandrel 73h to urge it downwardly relative to the valve sleeve 72h against the force of valve spring 334 until shoulders 332, 333 are engaged. The weight of the valve mandrel 73h and the sample chamber section 71, the diameter of the valve mandrel and the spring rate of the valve spring 334 are so chosen that the valve mandrel will be moved to its retracted position (FIG. 11) whenever a predetermined pump pressure is applied.

The upper side of the upper O-ring 352 around the valve mandrel 73h is exposed to the hydrostatic pressure within the bore of the pipe string and the lower face of the lower O-ring 353 around the valve mandrel is exposed to the hydrostatic pressure in the well bore annulus above the packing element 302 which is communicated through the body by-pass passage 317 and the sleeve by-pass passage 309. Therefore, the valve mandrel 73h is pressurebalanced within the valve sleeve 72h insofar as the hydrostatic head of drilling fluid is concerned so long as the 1 1 same hydrostatic head exists within and outside the pipe string 12.

The interior of the valve mandrel 73h is divided into two separate compartments by a bore-closing portion 355 near its lower end. The upper compartment 356 of the valve mandrel 73h forms a fluid conduit which opens into the chamber section 7111 and the lower compartment 357 forms a closed shut-in pressure chamber. Conventional time-pressure recorders 358 and 359 are mounted in each of the shut-in pressure chamber 357 and valve chamber section 71h respectively.

The retrievable valve assembly 20h has valve means similar to those already discussed in the prior embodiment for placing selectively either the shut-in pressure chamber 357 or both the shut-in pressure chamber and the upper compartment 356 in fluid communication with the sleeve member fluid passage 308. The valve means in this embodiment comprises a lateral passage 360 extending through the valve sleeve 72h between spaced O-rings 351 and 351a which seal the sleeve 72h within sleeve member 50h and a pair of longitudinally spaced lateral passages 361 and 362 extending into the valve mandrel 7311 on opposite sides of the bore-closing portion 355. The lateral passages 361 and 362 are so positioned and spaced that, in the extended position of mandrel 73h relative to valve sleeve 72h (FIG. the lower passage 361 through the mandrel registers with the valve sleeve passage 360, placing the shut-in pressure chamber 357 in fluid communication with the sleeve member fluid passage 308 (FIG. 12), and the passage 362 is closed by O-ring 352 and 363. In the retracted position of the mandrel 73h relative to the valve sleeve 72h (FIG. 11), both the lower and upper passages 361 and 362 communicate with sleeve passage 360. An enlarged section 364 of the bore of the valve sleeve 72h provides an annular passage for communication between the passage 361 and the sleeve fluid passage 360 when the mandrel 73h is in the retracted position.

In FIG. 14, the lower portion of a modified retrievable assembly is illustrated. The assembly 20 is adapted for use when taking the final fluid sample from a specified test zone. Modified assembly 20 differs from assembly 20h only in that the upper portion of the sampler valve sleeve 72 is enlarged in diameter to provide an unlocking head 365 and an overshot grapple member 366 is provided at the lower end of the valve mandrel 73 The enlarged-diameter portion of head 365 functions to release the sleeve member 50h from its locked lowermost position since it has suflicient diameter to retain the snap ring 316 in an expanded position as the retrievable assembly 20] is first raised from its seated position. The grapple member 366 may be of the conventional overshot type adapted to grip the retrieving head 367 of the barrier valve mandrel 339.

To perform testing operations within a well bore during drilling, the packer assembly 19h is connected to the end of the pipe string 12 with the drill bit 300 attached below as shown in FIG. 7. During the drilling operation, drilling fluid is normally circulated through the bore of the pipe string 12, passing downwardly through the bore of the bit 300 and thence upwardly through the annulus surrounding the pipe string 12. As shown in FIG. 7, the sleeve member 50h is held in its upper position by spring 313 and by snap ring 316 which is positioned in the recess 370 near the upper end of the sleeve member. In this position the body bypass passageway 317, the inflating passageway 304, and body fluid passage 320 are closed, and the deflating passage 305 is open.

When a zone to 'be tested is penetrated by the bit, drilling is halted and the retrievable assembly 20h with the barrier valve member 336 attached by shear pin 338 is lowered through the bore of the pipe string 12.

Upon reaching the packer assembly 19h, the retrievable assembly 20h is lowered as seen in FIG. 12 until the valve sleeve 72h is sealingly received within the sleeve member 50h. The weight of the retrievable valve assemt 12 bly 20h is suflicient for the tapered surface of slot 370 to momentarly expand the cam-acuated snap ring 316 and allow sleeve member 50h to move to its lowermost position and to compress the sleeve spring 313. Once the snap ring 316 is cleared, the uppermost face of sleeve member 5011 will be engaged by the lower face of snap ring 316 as it again contracts and the sleeve member will be secured in place. This downward movement of the sleeve member 50h opens the inflating passage 304 to the central bore of the body 301 and the tubing string 12. The sleeve 341 of the barrier valve member 336 is sealingly received within the reduced bore portion 321 in the lower end of the body member 301 and rests on 1 shoulder 314 so that the barrier valve mandrel 339 is lowered to its retracted position relative to the barrier sleeve 341.

The packer element 302 is inflated by applying pump pressure to the pipe string 12 at the surface to open inflating check valve 306 at the upper end of inflating passage 304 and inflate the packer element 302. When the pump pressure reaches a predetermined level (for example 500 p.s.i.g.), the packer element 302 will be sufliciently expanded for an effective pack-off of the zone therebelow.

At this step of the operation the valve mandrel 73h is in its uppermost position relative to the valve sleeve 72h of the retrievable assembly 20h. When the pump pressure is further increased to another predetermined value (for example 750 p.s.i.g.), the hydraulic pressure will move valve mandrel 73h downwardly relative to the valve sleeve 7 2h which is held in place by the engagement of shoulders 310, 315. The downward travel of the mandrel 73h shears pin 338 by which the retrievable barrier valve 336 was initially secured to the valve mandrel and allows the mandrel to move on downwardly to its lowermost position as illustrated in FIG. 11. Once the valve mandrel 73h reaches this position, formation fluids enter body fluid passage 320, pass through sleeve fluid passage 308 and valve sleeve passage 360 and enter lower and upper valve passages 361 and 362 to allow the pressure recorders 358 and 359 to record the initial formation flowing pressure.

If a shut-in pressure is desired, after a short time interval to relieve the hydrostatic drilling fluid pressure and the packer squeeze pressure trapped below the packer 302, the pump pressure in the bore of the pipe string 12 is reduced to return the valve mandrel 73h to its extended condition (FIG. 12) to terminate the flow into chamber 71h. If the formation has been permitted to flow only a brief period of time, the formation pressure will not have decreased materially and the lower.pressure recorder 358 will reporithe true or initial shut-in pressure. The pump pressure ma'y then' be raised above the predetermined value necessary to move the valve mandrel 73h to its retracted condition so as to complete the flow test and, if desired, the valve mandrel 73h may be maintained in this position for a sufiicient time to obtain a record of a final shut-in pressure, as well. As noted in the prior discussion of other embodiments, the flow test may be interrupted at any time and a remeasurement of shut-in pressure made.

During a series of tests at a particular test zone, the barrier valve member 336 remains seated in the lower portion of the body 301 of the well tool to prevent drilling fluid from entering the packed olf zone.

When the final sample is to be taken in this particular series of tests, the retrievable assembly 20h is recovered by the wireline 21. As seen in FIG. 13, the valve mandrel 73h and valve sleeve 72h are removed leaving sleeve member 50h secured in place by snap ring 316. The barrier valve assembly 336 remains seated in reduced bore portion 321. After the removal of the valve mandrel 73h and sleeve 72h, the bore of the packer assembly 19h is clear for entry of the retrievable assembly 20].

Thus, as seen in FIG. 14, the retrievable assembly 20] has been lowered in the packer assembly 19h and is now being retrieved. While in place within sleeve member 50h, the assembly 20 functions in the same manner as the valve assembly 20h to take test samples and measure formation pressures. As it is being seated in its operative position within the sleeve member 50h, the enlarged latching head 365 expands and holds the contractible split ring 316 outwardly and the depending fingers of grapple 366 will slip over and engage the retrieving head 367 of the barrier valve 366. At the conclusion of the desired sampling and pressure testing, the retrievable assembly 201' is raised by the wire-line 21. The snap ring 316 no longer constrains the upper end of sleeve member 50h so that during the initial upward travel of retrievable assembly 20 the sleeve member 50h is free to move upwardly and be returned to its uppermost position by spring 313. When the sleeve member 50h reaches the position illustrated in FIG. 14, it is again releasably locked in this position by the contractible snap ring 316 which snaps into the slot 370 of sleeve member 50h.

During this same initial upward movement of the retrievable assembly 20 the barrier mandrel 339 is also raised by the grapple fingers 366 until shoulder 370 on the mandrel engages shoulder 371 on the barrier sleeve 341. In this position, the port 340 is opened and pressures above and below the barrier valve member 336 are equalized through passage 342. This relieves hydrostatic pressure above the barrier valve 336 and facilitates its removal along with the retrievable assembly 20 After the retrievable assembly 20 and barrier valve 336 have been removed from the packer assembly 19 h, drilling may be resumed or the packer assembly 19h may 'be repositioned and further operations conducted.

The apparatus of this invention may be modified as indicated in the drawing of FIG. 15 to provide a retrievable valve assembly 20p adapted for the treating of a selected formation. This tool may be identical with any of the prior modifications of the retrievable valve assembly for all portions below the upper portion of the valve mandrel 73p containing the chamber 531. In this modification, a floating piston 532 is provided with O-rings 533 as an upper closure for the treating chamber 531. Near the upper end of the valve mandrel 73p, one or more lateral ports 535 are provided for fluid communication between the bore of the pipe string 12 and a hydraulic chamber 536 above the piston.

Suitable means to limit the upward travel of the floating piston 533 may be provided such as rod 537 which is of sufficient length to prevent the floating piston 532 from rising above the ports 535. The rod 537 may be conveniently attached to the cap 539.

For some applications, it may be desirable to omit the floating piston 533 in order to introduce through the bore of the pipe string large quantities of treating fluid which can be introduced into a test zone by means of ports 535.

The tool 20p may be used with acid or other desired treating material in the chamber 531. The treating material may be introduced into the chamber 531 by removing the cap 539 and piston 532. The filling operation may be facilitated by the use of a suitable jig to operate the valve sleeve of the retrievable valve assembly. The passage to the valve chamber 531 is then closed by manipulation of the jig and a supply of acid or other material introduced into the chamber 531 and the floating piston 532 is disposed thereabove. The tool 20p is then reassembled and introduced into the bore of the pipe string 12 in the manner previously described for testing operations. When the retrievable assembly 20p is seated within the packer assembly, pressure can be applied in the pipe string to open the chamber valve means. When the chamber 531 is placed in fluid communication with the packed-off zone of the well bore, the pump pressure within the pipe string 12 forces the floating piston 532 downwardly displacing the acid or treating fluid into the formation.

As one example of the use of treating chamber 531 of 2011 of FIG. 10; (2) removing the sample of fluid for analysis; (3) treating theiorrpati-on with acid usi ng the formation using, for example, the retrievable assembl treating ch a rnbe r- 531 of the retrievable assembly 20p; {4Treriioving the retrievable assembly 20p; and (5) conducing a further test of formation fluid by means of retrievable assembly 20h to determine the difference in production from the zone before and after acidizing.

If extensive acidizing should be required the retrievable assembly 20p may be used, omitting the floating piston 532 and large quantities of acid or other treating material may then be injected into the formation by pumping the acid through the drill string 12.

It may be noted that volatile materials or liquids under pressure or certain inert gases, such as carbon dioxide, are sometimes introduced as treating materials into a formation. A retrievable assembly of this invention, such as the embodiment of 20p, may be used for this purpose by introducing into the sample chamber the material in liquified form under high pressure. Such materials will normally have suflicient pressure at the temperatures of the well bore to overcome the hydrostatic pressure of the well fluid and/or any pressure in the test zone to permit the formation to be exposed to such gas, volatile liquid, or fluid under pressure when the valve mechanism of the retrievable assembly is opened in the manner previously described in connection with testing operations.

While particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects, and therefore the aim in the appended claims is to cover all such changes and modificatons as fall within the true spirit and scope of this invention.

What is claimed is:

1. A method of testing while drilling a well bore with a drilling string having hydraulically inflatable packing means thereon where said drill string has a control sleeve releasably operable to permit expansion or retraction of said packer means comprising the steps of: lowering a first sampling and sleeve control tool into the drill pipe when the drilling operation has been discontinued and operating said control sleeve to a releasable position where said packing means can be expanded; supplying fluid under pressure to expand said packing means into sealing engagement with the wall of the well bore and isolation of a section of a well bore; opening said sampling tool to collect a sample of fluid from the isolated section of said well bore; retrieving said first sampling tool without re leasing the control sleeve from its releasable position; performing one or more subsequent operations of lowering and retrieving a sampling tool from said drill pipe, each operation recovering a fluid sample and the packing means being continuously maintained in an expanded position; and during the last of said subsequent operations using a sampling tool with means to release said control sleeve.

2. A method of testing while drilling a well bore with a drilling string having inflatable packing means thereon comprising the steps of: supplying fluid under pressure to a packing means on a drilling string and expanding the packing means into sealing engagement With the Wall of the well; maintaining an inflating pressure in said packing means; lowering and retrieving sampling tools through the drilling string and collecting for each trip of a sampling tool a fluid sample; and after obtaining the last sample, deflating said packing means.

3. The method of claim 2 and further including the stem of measuring the pressure of the fluid sample while the tool is in the drilling string.

4. A method of testing while drilling a well bore with a drilling string having inflatable packing means thereon comprising the steps of: supplying fluid under pressure to a packing means on a drilling string and expanding the packing means into sealing engagement with the wall of the well; maintaining an inflating pressure in said packing means; performing at least two testing operations, each such operation including the lowering of a retrievable sampling tool through the drilling string, mgasuring of pressure in th e pipe string; measuring of pressure of fluids isolatedTTy the packing means before they are permitted to flow; measuring of pressure of fluid flowing from the section isolated by the packing means while collecting a fluid samplejrrieasuring of pressure of fluids isolated by the packing means after the fluids have been permitted to flow; and after obtaining the last samplefdeflating said packing means.

5. A method of performing operations while drilling a well bore with a drilling string having inflatable packing means thereon comprising the steps of: supplying fluid under pressure to said packing means on said drilling string to expand said packing means into sealing engagement with the wall of said well bore; maintaining an inflating pressure in said packing means; lowering and retrieving tools through the drilling string for performing operations below said packing means; and after performing the last operation, deflating said packing means.

6. A method of testing and treating while drilling a well bore with a drilling string having inflatable packing means thereon, comprising the steps of: supplying fluid under pressure to said packing means on said drilling string to expand said packing means into sealing engagement with the wall of said well bore, thereby isolating a formation zone; maintaining an inflating pressure in said packing 'means; conducting a first test of formation fluids from said isolated zone; thereafter treating the isolated zone withg trgatingfi lidg, conducting a second test of formation fluid from the isolated zone for comparison with said first test results; and then deflating said packing means.

7. A method of performing formation testing operations in a well bore having a pipe string positioned therein with inflatable packing means on the pipe string comprising the steps of: supplying fluid under pressure to said packing means on said pipe string to expand said packing means into sealing engagement with the wall of the well bore, thereby isolating a formation zone; maintaining an inflating pressure in said packing means; lowering and retrieving fluid sampling tools through the pipe string for performing testing operations adjacent the isolated zone; and after performing the last testing operation, deflating said packing means.

References Cited UNITED STATES PATENTS 2,404,825 7/1946 Brown et a1 166142 X 2,611,437 9/1952 Lynes 27734.6 2,831,541 4/1958 Conover 166-147 2,978,046 4/1961 True 166162 X 3,111,169 11/1963 Hyde 166145 OTHER REFERENCES Bleakley, W. B. Modern Drill-Stem Testing, The Oil and Gas Journal, Dec. 22, 1958, vol. 56, No. 51, pp. 59- 63.

CHARLES E. OCONNELL, Primary Examiner.

D. H. BROWN, Assistant Examiner. 

7. A METHOD OF PERFORMING FORMATION TESTING OPERATIONS IN A WELL BORE HAVING A PIPE STRING POSITIONED THEREIN WITH INFLATABLE PACKING MEANS ON THE PIPE STRING COMPRISING THE STEPS OF: SUPPLYING FLUID UNDER PRESSURE TO SAID PACKING MEANS ON SAID PIPE STRING TO EXPAND SAID PACKING MEANS INTO SEALING ENGAGEMENT WITH THE WALL OF THE WELL BORE, THEREBY ISOLATING A FORMATION ZONE; MAINTAINING AN INFLATING PRESSURE IN SAID PACKING MEANS; LOWERING AND RETRIEVING FLUID SAMPLE TOOLS THROUGH THE PIPE STRING FOR PERFORMING TESTING OPERATIONS ADJACENT THE ISOLATED ZONE; AND AFTER PERFORMING THE LAST TESTING OPERATION, DEFLATING SAID PACKING MEANS. 